Magnetic stripe cards are plastic cards that contain a magnetic stripe on the back, which stores data. This data can include information such as account numbers and cardholder details. When swiped through a card reader, the magnetic stripe allows for quick access to this information, enabling transactions in various settings like retail stores and ATMs. These cards are commonly used for payment methods, such as credit and debit cards, as well as identification purposes, like employee ID cards and library cards. The magnetic stripe technology has been widely adopted due to its convenience, although it is gradually being replaced by more secure options like chip cards.